A large variety of multi-speed transmissions for heavy duty trucks which must operate at highway speeds have heretofore been proposed. Thus, six-speed and eleven-speed transmissions are common in the art and a number of such transmissions have been heretofore equipped with an overdrive gearing condition wherein the drive ratio is on the order of 0.84 to 1.
Such prior art transmissions have normally employed the extended H pattern of shifting, with which every truck operator is intimately familiar, until it was desired to shift from direct drive to overdrive, whereupon the transmission lever was moved contrary to the normal movement pattern expected with the extended H shift pattern. As a result, it has been observed that drivers frequently shift prematurely into the overdrive condition by instinctively following the movements of the extended H shifting pattern. For example, in a six-speed transmission, prior art mechanisms have positioned the sixth-speed (normally the direct drive condition) of the gear shift lever at the rearward end of the last leg of the extended H shifting configuration, and the overdrive condition required the shift lever be moved to the forward end of such last leg. The result is that the operator, in shifting up from the next to the last leg, quite often habitually went directly into the overdrive position, skipping the direct drive position, and thus putting unnecessary load on the engine.